Comparison of the effects of 10.6-μm infrared laser and traditional moxibustion in the treatment of knee osteoarthritis

Based on two separate randomized controlled trials (RCTs) on traditional Chinese medicine (TCM) moxibustion and 10.6-μm infrared laser moxibustion in treating knee osteoarthritis (OA), we did an indirect and preliminary comparison of the effects of the 10.6-μm laser moxibustion with the traditional moxibustion for knee osteoarthritis. The objective was to see whether the laser moxibustion is non-inferior to the traditional moxibustion in alleviating symptoms of knee osteoarthritis such as pain, stiffness, and joint dysfunction as well as improving quality of life for the patients with knee osteoarthritis, and whether a further RCT directly comparing the laser and traditional moxibustion is necessary. Pooled data from two RCTs in patients with knee osteoarthritis, trial ISRCTN68475405 and trial ISRCTN26065334, were used. In the two RCTs, the eligibility criteria were almost identical, the treatment procedure (i.e., sessions, duration, and points) were similar, and the outcome measurements (i.e., WOMAC for symptoms and SF-36 for quality of life) were the same. The double robustness method was used for the WOMAC scale and the SF-36 endpoints to detect the difference between traditional and laser moxibustion. The analysis comprised 55 patients from ISRCTN68475405 in real moxibustion arm (moxibustion group) and 88 patients from ISRCTN26065334 in real laser moxibustion arm (laser group). Demographic characteristics and course of disease were similar between the two groups. Causal inference, using the doubly robust estimating approach to correct for bias due to baseline differences, showed that there was no statistically significant difference in the WOMAC pain, stiffness, and physical function between the two treatments at midterm, end of treatment, and 4 weeks after the end of treatment (P > 0.05). The exception was that there was statistically significantly more benefit associated with laser moxibustion compared with traditional moxibustion in physical function at the follow-up of 4 weeks after the end of treatment (P=0.006). There was no statistically significant difference in most SF-36 endpoints (P > 0.05) except that physical functioning (PF), mental health (MH), and bodily pain (BP) were statistically significantly better in the laser group than in the traditional moxibustion group at the follow-up of 4 weeks after the end of treatment (P = 0.005, 0.034, 0.002). The benefits of 10.6-μm infrared laser moxibustion and the traditional moxibustion for knee osteoarthritis were comparable in pain, stiffness, physical dysfunction, and in most of the quality of life subdimensions. The laser moxibustion might be more beneficial in terms of physical function, body pain, and mental health in the long term. RCTs directly comparing 10.6-μm laser moxibustion with traditional moxibustion are warranted.